There are a wide variety of applications in which irrigation control is used to ensure optimum watering of crops and landscaping. In general, irrigation is used to supplement natural rainfall, but frequently it is used in addition to rainfall, often leading to overwatering and therefore wasteful watering. The conservation of water supplies is of paramount concern, so it is of interest to not water when natural rainfall has occurred sufficient to meet the watering needs of a region for a given period.
Many manufacturers have designed systems that inhibit watering upon the occurrence of rain by using local sensors that measure rainfall or soil moisture. However these systems are prone to inaccurate readings and breakage of the sensor equipment. Furthermore, irrigation controllers typically require a commercial electric power source because of the frequent operation of circuitry. This limits the ease of deployment of irrigation controllers, or adds to the cost by requiring the laying of power lines to areas to be serviced by irrigation controllers.
Those skilled in the field of the present disclosure will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. The details of well-known elements, structure, or processes that would be necessary to practice the embodiments, and that would be well known to those of skill in the art, are not necessarily shown and should be assumed to be present unless otherwise indicated.